In 1999, a new self-report outcome measure, the Functional Rating Index (FRI), was developed and tested. This measure demonstrated reasonable reliability, validity and responsiveness. Since the publication of the original testing, numerous independent research teams have examined the psychometric qualities of the FRI and published their findings. The aim of this study is to review the psychometric properties of the FRI as reported by published studies. Researchers independently searched the literature for relevant studies using MEDLINE and Index to Chiropractic Literature from January 2001 to August 2009. Descriptive and outcome data was extracted using standardized forms. The psychometric properties of the FRI were analyzed with established criteria and compared head-to-head with other outcome measures. The search yielded ten studies that provided psychometric data. Reliability: Test-retest: Intraclass correlation coefficient and Cronbach's alpha were good, and FRI is equivalent to the other measures.

Validity: the FRI has good convergent validity with pain and function self-report scales and a weaker correlation with items that measure different constructs. Responsiveness: FRI was similar to the comparative measures for standardized response mean, effect size and receiver operating curve statistics. Patient acceptability: time required by the patient and staff averaged 78 seconds per administration, and there were few missing responses. The FRI demonstrates favorable measurement properties of reliability, validity and responsiveness. It provides an alternative to other self-report measures, because it is quicker for a patient to complete and can be used for patients with neck and back pain.